rt's action, as evidenced by improved volume and
slower pulse rate, the augmentation of the temperature,
increased activity of the skin, fuller and slower respiration,
gradually increased respiratory capacity, and diminished
irritability of the mucous membrane in tubercular, bronchitic,
or asthmatic patients. There is also lessened discharge in
those patients suffering from catarrhal conditions of the nasal
passages. In diseases of the respiratory system, a soothing
effect upon the mucous membranes is always experienced, while
cough and expectoration are diminished.

The cabinet used by Dr. Cleaves was large enough to contain a cot upon
which the patient reclined. An arc-lamp was suspended at each of the two
ends of the cabinet and a flood of light was obtained directly and by
reflection from the white inside surfaces of the cabinet. By means of
mirrors the light from the arcs could be concentrated upon any desired
part of the patient.

Finsen, who in 1895 published his observations upon the stimulating
action of light, is considered the pioneer in the use of so-called
chemical rays in the treatment of disease. He had a circular room about
thirty-seven feet in diameter, in which two powerful 100-ampere
arc-lamps about six feet from the floor were suspended from the ceiling.
Low partitions extended radially from the center, so that a number of
patients could be treated simultaneously. The temperature of the room
was normal, so that the treatment was essentially by radiant energy and
not by heat. The chemical action upon the skin was said to be quite as
strong as under sunlight. The exposures varied from ten minutes to an
hour.

Light-baths containing incandescent filament lamps are also used. In
some cases the lamp, sometimes having a blue bulb, is merely contained
as a reflector and the light is applied locally as desired.
Light-cabinets are also used, but in these there is considerable effect
due to heat. The ultra-violet rays emitted by the small electric
filament lamps used in these cabinets are of very low intensity and the
bactericidal action of the light must be feeble. The glass bulbs do not
transmit the extreme ultra-violet rays responsible for the production of
ozone, or the middle ultra-violet rays which are effective in destroying
animal tissue. The cabinets contain from twenty to one hundred
incandescent filament lamps of the ordinary sizes, from 25 to 60 watts